idnits 2.17.1 draft-zhang-pce-locate-asbr-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** It looks like you're using RFC 3978 boilerplate. You should update this to the boilerplate described in the IETF Trust License Policy document (see https://trustee.ietf.org/license-info), which is required now. -- Found old boilerplate from RFC 3978, Section 5.1 on line 15. -- Found old boilerplate from RFC 3978, Section 5.5 on line 308. -- Found old boilerplate from RFC 3979, Section 5, paragraph 1 on line 285. -- Found old boilerplate from RFC 3979, Section 5, paragraph 2 on line 292. -- Found old boilerplate from RFC 3979, Section 5, paragraph 3 on line 298. ** This document has an original RFC 3978 Section 5.4 Copyright Line, instead of the newer IETF Trust Copyright according to RFC 4748. ** This document has an original RFC 3978 Section 5.5 Disclaimer, instead of the newer disclaimer which includes the IETF Trust according to RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- == No 'Intended status' indicated for this document; assuming Proposed Standard Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** There are 2 instances of too long lines in the document, the longest one being 1 character in excess of 72. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (October 12, 2006) is 6399 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: '1' is mentioned on line 48, but not defined == Missing Reference: 'I-D.ietf-ccamp-inter-domain-framework' is mentioned on line 71, but not defined == Unused Reference: 'RFC4655' is defined on line 249, but no explicit reference was found in the text == Unused Reference: 'BGP-MP' is defined on line 252, but no explicit reference was found in the text == Unused Reference: '2' is defined on line 257, but no explicit reference was found in the text == Unused Reference: 'BGP-CAP' is defined on line 261, but no explicit reference was found in the text == Outdated reference: A later version (-09) exists of draft-ietf-pce-brpc-00 ** Downref: Normative reference to an Informational RFC: RFC 4655 ** Obsolete normative reference: RFC 2858 (ref. 'BGP-MP') (Obsoleted by RFC 4760) -- Obsolete informational reference (is this intentional?): RFC 3392 (ref. 'BGP-CAP') (Obsoleted by RFC 5492) Summary: 6 errors (**), 0 flaws (~~), 9 warnings (==), 8 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Network Working Group Renhai. Zhang 2 Mach. Chen 3 Internet Draft Huawei Technologies Co.,Ltd 4 Expires: March 2007 October 12, 2006 6 Locate ASBR in PCE 7 draft-zhang-pce-locate-asbr-00.txt 9 Status of this Memo 11 By submitting this Internet-Draft, each author represents that 12 any applicable patent or other IPR claims of which he or she is 13 aware have been or will be disclosed, and any of which he or she 14 becomes aware will be disclosed, in accordance with Section 6 of 15 BCP 79. 17 Internet-Drafts are working documents of the Internet Engineering 18 Task Force (IETF), its areas, and its working groups. Note that 19 other groups may also distribute working documents as Internet-Drafts. 21 Internet-Drafts are draft documents valid for a maximum of six months 22 and may be updated, replaced, or obsoleted by other documents at any 23 time. It is inappropriate to use Internet-Drafts as reference 24 material or to cite them other than as "work in progress." 26 The list of current Internet-Drafts can be accessed at 27 http://www.ietf.org/ietf/1id-abstracts.txt 29 The list of Internet-Draft Shadow Directories can be accessed at 30 http://www.ietf.org/shadow.html 32 This Internet-Draft will expire on April 12, 2007. 34 Abstract 36 The ability to compute constrained shortest Traffic Engineering (TE) 37 Label Switched Paths (LSPs) in Multiprotocol Label Switching (MPLS) 38 and Generalized MPLS (GMPLS) networks across multiple domains has 39 been identified as a key requirement. This document specifies a 40 procedure for an inter-AS PCE to locate boundary node within its 41 domain dynamically, which is used for path computation. 43 Conventions used in this document 45 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 46 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 47 document are to be interpreted as described in RFC-2119 [1]. 49 Table of Contents 51 1. Introduction................................................2 52 2. BGP extension...............................................3 53 2.1. EBGP Session Summary NLRI..............................3 54 2.2. ESSNP capability.......................................4 55 3. Procedure...................................................4 56 4. Example.....................................................5 57 5. Security Considerations.....................................6 58 6. IANA Considerations.........................................6 59 7. References..................................................6 60 7.1. Normative References...................................6 61 7.2. Informative References.................................6 62 Author's Addresses.............................................7 63 Intellectual Property Statement................................7 64 Disclaimer of Validity.........................................7 65 Copyright Statement............................................8 66 Acknowledgment.................................................8 68 1. Introduction 70 The framework for inter-domain MPLS Traffic Engineering has been 71 provided in [I-D.ietf-ccamp-inter-domain-framework]. 73 An inter-AS PCE must have reachability information to the LSP tail- 74 end and head-end. At minimum, this reachability information must 75 include the AS path to the LSP tail-end, and the AS in which the 76 tail-end and head-end of the LSP reside. Using this information, an 77 inter-AS PCE can determine whether it can fully handle the path 78 computation request by itself. PCE may obtain the reachability 79 information using PCECP protocol extension, which is running between 80 the ASBR and PCE. But this may increase the complexity of the ASBR. 81 At the same time, PCE need make a selection among many ASBRs. So an 82 IBGP session between an inter-AS PCE and each ASBR is a better choice. 84 [BRPC] defines a PCE-based TE LSP computation method to compute 85 optimal inter-domain constrained (G)MPLS TE LSPs. In this path 86 computation method, an inter-AS PCE needs to locate ASBRs that 87 provide connectivity from a specified AS. 89 Network administrator could configure ASBRs information on the inter- 90 AS PCE. But it may not be the best way. When the inter-AS link of an 91 ASBR is down, the PCE may proceed the path computation without being 92 aware of the situation.. Of course the result is that it can not get 93 a successful path through this ASBR. In order to solve the problem, 94 this document provides a method by which the PCE can dynamically 95 obtain information on the ASBR and its interconnected AS. 97 According to the above statement, MP-BGP is a good choice for an 98 inter-AS PCE to achieve necessary information used in BRPC method. 99 Thus, some extension to BGP is needed. 101 2. BGP extension 103 EBGP speaker should report its connections to the inter-AS PCE. A new 104 NLRI named EBGP Session Summary NLRI is introduced with extension to 105 MP-BGP. 107 2.1. EBGP Session Summary NLRI 109 The EBGP Session Summary NLRI is described below. A new AFI and SAFI 110 need to be defined. 112 +------------------------------------+ 113 | Length (2 octets) | 114 +------------------------------------+ 115 | Router ID (4 octets) | 116 +------------------------------------+ 117 | AS Number (2 octets) | 118 +------------------------------------+ 119 / / 120 / / 121 / / 122 +------------------------------------+ 123 | Router ID (4 octets) | 124 +------------------------------------+ 125 | AS Number (2 octets) | 126 +------------------------------------+ 128 The use and the meaning of these fields are as follows: 130 a) Length: 132 The Length field indicates the length in bytes of the whole 133 NLRI. 135 b) Router ID: 137 This field indicates the Router ID of the peer BGP speaker in 138 the neighboring AS. 140 c) AS Number: 142 This field indicates the AS number of the BGP peer. 144 The tuple of means an EBGP peer in a 145 neighboring AS. It could appear more than once in the NLRI. With this 146 information received from all EBGP speakers within its AS, an inter- 147 AS PCE can have the knowledge of ASBRs in its AS and neighboring AS 148 needed in path computation. 150 2.2. ESSNP capability 152 New AFI and SAFI need to be defined and negotiated during BGP session 153 establishment. It represents a capability to process EBGP Session 154 Summary NLRI. We named this capability ESSNP (EBGP Session Summary 155 NLRI Processing) here. 157 As inter-AS PCE establish IBGP connections with all BGP speakers 158 within its scope, with the ESSNP capability, it can have knowledge of 159 the ASBRs within its domain and their corresponding interconnection 160 of all neighboring ASes. Thus, when it computes using BRPC method, it 161 can find appropriate ASBR. 163 3. Procedure 165 When an ASBR establishes a new IBGP session with an inter-AS PCE, 166 they SHOULD negotiate ESSNP capability firstly. Upon succeeding, the 167 ASBR SHUOLD encapsulate each EBGP connection information in EBGP 168 Session Summary NLRI, and send them to the PCE. 170 When an EBGP speaker establishes a new EBGP connection, it SHUOLD 171 encapsulate this connection information in EBGP Session Summary NLRI 172 and send an update message to all the inter-AS PCEs that support 173 ESSNP capability within the AS it resides in. 175 When an EBGP connection of a speaker is down, it SHUOLD encapsulate 176 this connection information in EBGP Session Summary NLRI and send a 177 withdraw message to all the inter-AS PCEs that support ESSNP 178 capability within the AS it resides in. 180 4. Example 182 An inter-AS PCE SHOULD build an EBGP Session Summary table to 183 efficiently maintenance those information received from ASBR within 184 its AS scope, using AS number or AS number combined with the Router 185 ID of a neighboring ASBR as index to look up the local ASBR needed in 186 computation. 188 Let's see an example as follows: 190 Inter-AS Inter-AS Inter-AS 191 PCE1<---------->PCE2<--------------> PCE3 192 :: :: :: 193 R1---ASBR1====ASBR3---R3---ASBR5====ASBR7---R5---R6 194 | | | | / | 195 | | | | / | 196 | | | | / | 197 R2---ASBR2====ASBR4---R4---ASBR6 / R7 198 <==AS1=> <====AS2======> <=====AS3===> 199 Figure 1 Inter-AS PCE Reference Model 201 Assume that PCE1 received a computation request from R1 to R6. Then, 202 this request is relayed to PCE3 eventually. The EBGP Session Summary 203 table of PCE3 may be like this: 205 AS number Router ID Local ASBR 206 -------------------------------------------- 207 AS2 ASBR5 ASBR7 208 AS2 ASBR6 ASBR7 209 Table 1: The EBGP Session Summary table for PCE3 211 PCE3 knows the request arriving from AS2. So it looks up Table 1 and 212 finds the only ASBR connecting to AS2 is ASBR7. PCE3 computes and 213 passes the result ASBR7-R5-R6-R7 to PCE2. 215 The EBGP Session Summary table of PCE2 may be like this: 217 AS number Router ID Local ASBR 218 -------------------------------------------- 219 AS1 ASBR1 ASBR3 220 AS1 ASBR2 ASBR4 221 AS3 ASBR7 ASBR5, ASBR6 222 Table 2: The EBGP Session Summary table for PCE2 224 Using AS3 and ASBR7 as index to look up Table 2, PCE2 will locate the 225 ASBR in AS2 connecting to ASBR7 is ASBR5 and ASBR6. At the same time, 226 PCE2 should locate ASBR connecting to AS1 because it should compute 227 the path from those ASBRes to R7 and pass the partial result to PCE1. 228 Using AS1 as index it will find ASBR3 and ASBR4. The computation 229 continues as described in [BRPC]. 231 5. Security Considerations 233 No new security issues are raised in this document. 235 6. IANA Considerations 237 IANA is asked to allocate an AFI and SAFI for EBGP Statistic NLRI. 239 7. References 241 7.1. Normative References 243 [BRPC] JP. Vasseur, Ed., R. Zhang, N. Bitar, JL. Le Roux, " A 244 Backward Recursive PCE-based Computation (BRPC) procedure 245 to compute shortest inter-domain Traffic Engineering Label 246 Switched Paths ", draft-ietf-pce-brpc-00.txt, Work in 247 Progress, August 2006. 249 [RFC4655] A. Farrel, J.-P. Vasseur, J. Ash, " A Path Computation 250 Element (PCE)-Based Architecture ", RFC 4655, August 2006. 252 [BGP-MP] T. Bates, Y. Rekhter, R. Chandra, D. Katz, " Multiprotocol 253 Extensions for BGP-4 ", RFC 2858, June 2000. 255 7.2. Informative References 257 [2] Nabil Bitar, Jean-Louis Le Roux, Raymond Zhang, " Framework for 258 PCE based inter-domain path computation ", draft-bitar-pce- 259 inter-domain-frwk-00.txt, Work in Progress, June 2006. 261 [BGP-CAP] R. Chandra, J. Scudder, " Capabilities Advertisement with 262 BGP-4 ", RFC 3392, November 2002. 264 Author's Addresses 266 Renhai Zhang 267 Huawei Technologies Co.,Ltd 269 Email: zhangrenhai@huawei.com 271 Mach chen 272 Huawei Technologies Co.,Ltd 274 Email: mach@huawei.com 276 Intellectual Property Statement 278 The IETF takes no position regarding the validity or scope of any 279 Intellectual Property Rights or other rights that might be claimed to 280 pertain to the implementation or use of the technology described in 281 this document or the extent to which any license under such rights 282 might or might not be available; nor does it represent that it has 283 made any independent effort to identify any such rights. Information 284 on the procedures with respect to rights in RFC documents can be 285 found in BCP 78 and BCP 79. 287 Copies of IPR disclosures made to the IETF Secretariat and any 288 assurances of licenses to be made available, or the result of an 289 attempt made to obtain a general license or permission for the use of 290 such proprietary rights by implementers or users of this 291 specification can be obtained from the IETF on-line IPR repository at 292 http://www.ietf.org/ipr. 294 The IETF invites any interested party to bring to its attention any 295 copyrights, patents or patent applications, or other proprietary 296 rights that may cover technology that may be required to implement 297 this standard. Please address the information to the IETF at 298 ietf-ipr@ietf.org. 300 Disclaimer of Validity 302 This document and the information contained herein are provided on an 303 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 304 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET 305 ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, 306 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE 307 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 308 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 310 Copyright Statement 312 Copyright (C) The Internet Society (2006). 314 This document is subject to the rights, licenses and restrictions 315 contained in BCP 78, and except as set forth therein, the authors 316 retain all their rights. 318 Acknowledgment 320 Funding for the RFC Editor function is currently provided by the 321 Internet Society.